Association between illness perception and social alienation among maintenance hemodialysis patients: The mediating role of fear of progression

Purpose This study aimed to investigate the mediating role of fear of progression on illness perception and social alienation among maintenance hemodialysis (MHD) patients. Background MHD is frequently accompanied by increased pain and complications such as itchy skin, chronic fatigue, and muscle spasms. Cardiovascular disease rates are also elevated among MHD patients, which can heighten their anxiety regarding prognosis and treatment discomfort. This chronic fear may severely impact social functioning, leading patients to withdraw from interpersonal interactions and experience heightened helplessness and loneliness. Further investigation is necessary to understand the factors behind the high level of social alienation in MHD patients and their underlying mechanisms. Design A cross-sectional study guided by the STROBE. Methods A convenience sample of 230 MHD patients were enrolled from January to May 2023. Data including demographic and clinical characteristics, illness perception, fear of progression, and social alienation were collected. Descriptive analysis and Pearson correlations were conducted using IBM SPSS version 25.0. The mediating effect was analyzed using Model 4 of the PROCESS macro for SPSS, with the Bootstrap method employed to assess its significance. Results The score of social alienation in MHD patients was high, with illness perception and fear of progression both significantly correlated with social alienation. In the mediating effects model, illness perception can predict social alienation in MHD patients, and fear of progression use plays a part in mediating the process by which illness perception affects social alienation. The Kappa Squared (κ2) value of 21.9%, suggests a medium effect size. Conclusions Illness perception directly predicts social alienation in MHD patients and exerts an indirect effect through the mediating role of fear of progression. Suggests that healthcare professionals should concentrate on MHD patients with high negative illness perceptions to alleviate their fear of progression, thereby decreasing the level of social alienation and enhancing their integration into society.


Introduction
End-stage renal disease (ESRD), a progressive and debilitating condition characterized by the advanced deterioration of kidney function, presents a substantial and formidable health risk [1].ESRD patients need to undergo kidney replacement therapy (KRT) for treatment, which is relied upon by 3.9 million people worldwide [2,3].Among the various forms of KRT, maintenance hemodialysis (MHD) is the most widely used and accepted, accounting for about 69% of all KRT and 89% of all dialysis cases [4].MHD has proven to be prolonging the lives of ESRD patients [5,6].However, With the continuous advancement of the new model of modern biopsychosocial medicine [7], the prolongation of a patient's life is no longer regarded as the only index for evaluating the treatment effect; and the nursing model should be transformed from the traditional therapeutic nursing to the nursing care model should also be changed from traditional curative care to comprehensive care, i.e., healthcare personnel should provide psychosocial services for patients while emphasizing on relieving their clinical symptoms, to better improve the quality of care [8].That is to say, medical and nursing staff should not only emphasize relieving patients' clinical symptoms but also provide patients with psychosocial services, to better improve their quality of life during the survival period.
According to the definition requirements of the World Health Organization (WHO), the quality of survival is a multidimensional concept, which includes four aspects: physiological, psychological, social functioning, and material status, while the diagnosis of ESRD and the treatment of MHD, in addition to causing physiological discomfort and pain to the patient, will also affect the patient's psychological status and social functioning, leading to the patient's physical and mental health, social participation, and other aspects of the situation is not optimistic [9].MHD patients suffer from more complications than others, such as chronic pain [10,11], itchy skin [12], chronic fatigue [13] and muscle spasms [14], etc.Meanwhile, the incidence and mortality rates of cardiovascular diseases in MHD patients are higher than those in the general population [15], so the uncertainty of the disease prognosis, coupled with the pain caused by the treatment, can lead to feelings of worry and fear in patients.Chronic and excessive fear of disease progression affects patients' social functioning [16], prompting MHD patients to choose to withdraw and distance themselves from daily interpersonal interactions, which in turn leads to helplessness and loneliness [17], that is, a state of "social alienation".Social alienation refers to the perception of negative treatment by the outside world when engaging in social interactions, leading to a sense of estrangement from others and society [18].It encompasses subjective emotions such as loneliness and indifference, as well as objective behaviors such as rejection and avoidance.Studies have shown that social alienation was associated with an increase in poor health behaviors, including decreased physical activity, unhealthy dietary patterns, and increased suicidal ideation [19,20].Unhealthy lifestyle choices and dietary patterns have been widely acknowledged as risk factors for a range of diseases, including cardiovascular disease [21][22][23].Pertinently, these factors can also exert a significant impact on the management and control of kidney disease [24].Research has shown that MHD patients suffer from extensive and significant social alienation [25], which has a severe impact on all aspects of their physical, mental, and social health.Therefore, there exists an immense significance in quantifying the level of social alienation among MHD patients and comprehensively scrutinizing its potential associations with various variables.
Illness perception (IP) is defined as individuals' use of prior illness cognitions and experiences to analyze, regulate, and modify their current illness or threatened health state [26].In the Common-Sense model of Self-Regulation (CSM) [27], both patients' cognitive and affective perceptions of illness hold substantial sway over their overall well-being and emotional state, which subsequently exert influence on their adaptive coping mechanisms, including the inclination towards social withdrawal.The correlation between IP and social interaction has been demonstrated in many patients with chronic diseases.Prior investigations have established a compelling association between illness perception (IP) and social alienation across various patient cohorts, including those affected by interstitial lung disease [28], cancer [29,30], and nonepileptic seizures [31].It is with this backdrop that we proffer a well-founded conjecture, hypothesizing an intrinsic correlation between IP and social alienation.
Fear of progression (FOP) is very common and has been the focus of research in recent years across a variety of chronic diseases [32,33].In its essence, the term encompasses an individual's instinctual and cognizant apprehension of the intricate ramifications of disease progression, spanning the realms of biology, psychology, and society [34].Although moderate fear-induced defensive behaviors are beneficial to the patient's physical health, prolonged and excessive fear can lead to adverse outcomes and induce social avoidance behaviors in patients [35].Studies have demonstrated that heightened concerns regarding disease progression predict higher levels of psychosocial distress in patients [36].However, as far as our knowledge extends, the possible mediating role of FOP between IP on social alienation has not been explored in the current research.Therefore, we hypothesized that FOP mediates IP and social alienation.
Taking into account the above overview, our study set out to investigate Chinese MHD patients, quantifying the extent of social alienation in MHD patients and identifying potential mechanisms involved.First, we hypothesized that MHD patients have high levels of social alienation.Second, we hypothesized a correlation between IP and social alienation.Finally, we hypothesized that FOP mediates IP and social alienation.Therefore, we propose the following research hypotheses, as illustrated in Fig 1.

Design
The study employed a cross-sectional correlational study survey design and complied with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist.

Sample
We used a convenience sampling method to select MHD patients who attended a hemodialysis center in three tertiary hospitals in Wuhan, Hubei province, from January 2023 to May 2023.
The criteria for participant inclusion in this study encompassed the following key aspects:

Sample size
The sample size was calculated using G-Power 3.1.9.7.The calculations were based on an α level of 0.05, power of 0.95, medium effect size of 0.25, and considering a 20% sample loss rate.The minimum required sample size was determined to be 168 cases.A total of 250 questionnaires were distributed in this study and 230 questionnaires were validly returned with a validity rate of 92%, which satisfied the minimum sample size required for this study.

Variables and instruments
Demographic and clinical characteristics.Demographic data includes MHD patients' age, gender, education level, marital status, and monthly income.Clinical information included primary cause, number of comorbidities, duration of hemodialysis, and frequency of dialysis frequency.
Illness perception.The assessment of IP was performed using the Brief Illness Perception Questionnaire (BIPQ) [37].Developed by Broadbent [38], the BIPQ was employed to evaluate patients' cognitive and emotional reactions toward their illness.The questionnaire comprised nine items, each rated on a scale of 0 to 10, except for the item about the perceived cause of the disease.The total score ranged from 0 to 80, with higher scores signifying heightened negative perceptions of the disease and greater severity of its symptoms.Item 9 of the questionnaire entailed an open-ended inquiry, wherein patients were prompted to pinpoint the three most substantial factors contributing to their illness.Widely used in the MHD patients, this scale has demonstrated a Cronbach's alpha coefficient of 0.757 [39].In the present study, the scale demonstrated a Cronbach's α coefficient of 0.829, indicating good internal consistency.
Fear of progression.The assessment of FOP was performed using the Fear of Progression Questionnaire-Short Form (FoP-Q-SF) [40].Developed by Mehner, the FoP-Q-SF was specifically designed to evaluate the degree of fear experienced by patients with chronic diseases regarding disease progression or relapse.The scale employed in this study comprises 12 items and encompasses two dimensions: physical health and socio-family aspects.Each item was evaluated using a five-point Likert scale, spanning from "never" to "always," generating a composite score ranging from 12 to 60. Higher scores are indicative of an intensified apprehension regarding the progression of the disease.Notably, if the total score equals or exceeds 34, it signifies the presence of psychological dysfunction in the patient.This scale is currently widely utilized among renal dialysis patients in China, demonstrating a Cronbach's alpha coefficient of 0.895 [41].In the present study, the scale demonstrated a Cronbach's α coefficient of 0.727, indicating good internal consistency.
Social alienation.The assessment of Social alienation was performed using the General Social Alienation Scale (GSAS) [42].The GSAS, developed by Jessor [42], was utilized to assess the degree of social alienation by individuals.The scale comprises a total of 15 items, encompassing four distinct dimensions: social alienation, powerlessness, self-alienation, and meaninglessness.Each item was assessed using a 4-point Likert scale, spanning from "strongly disagree" to "strongly agree," with a range of 1 to 4. As a result, the overall score ranged from 15 to 60, with higher scores denoting heightened levels of alienation.The GSAS is widely employed among MHD patients in China, demonstrating a Cronbach's alpha coefficient of 0.805 [43].In the present study, the scale demonstrated a Cronbach's α coefficient of 0.831, indicating good internal consistency.

Data collection
Structured paper-and-pencil questionnaires were utilized for data collection, encompassing four distinct sections: demographic and clinical information, IP, FOP, and social alienation.We tried to distribute the questionnaires at times when they were not fatigued, such as before the start of hemodialysis or within 1 to 2 hours after the start.For patients who were not convenient to fill in the questionnaire, the investigator asked for and recorded each item.We distributed, monitored, and collected the questionnaires on-site, actively addressing inquiries raised by the study participants.Subsequently, we inspected the retrieved questionnaires to ensure their completeness, considering any missing responses as invalid for patients who abandoned questionnaire completion midway through the process.The data underlying this research can be found in the S1 Data.

Data analysis
Statistical analyses were performed employing IBM SPSS version 25.0.All statistical tests are two-way (α = 0.05).Count data were described by frequency and composition ratio, whereas measurement data that conform to the normal distribution were described by the mean and standard deviation (SD) and compared between groups using independent samples t-test and one-way ANOVA.The measurement data that did not conform to a normal distribution were described by the median and quartiles, and the Mann-Whitney U test and Kruskal-Wallis H test was used for comparison between groups.To investigate the relationships between IP, FOP, and social alienation, the Pearson correlation coefficient was utilized.
Mediation analysis was performed using Model 4 of the PROCESS macro for SPSS [44].In our statistical analyses, social alienation was used as the dependent variable, IP as the independent variable, and FOP as the mediating variable.We controlled for the following demographic variables and clinical information: age, gender (0 = male, 1 = female), education level (four dummy-coded variables), marital status (two dummy-coded variables), monthly income (three dummy-coded variables), primary cause (four dummy-coded variables), number of comorbidities (three dummy-coded variables), duration of hemodialysis (three dummy-coded variables), and dialysis frequency (two dummy-coded variables).
The mediating role of FOP was examined using the bootstrap resampling approach with 5000 bootstrap samples and a 95% confidence interval (CI) around the standardized estimate.The point estimates and 95% CI of the direct effects, indirect effects, and total effects were assessed using bootstrapping with 5,000 simulations.A statistically significant effect was determined if the 95% CI interval excluded zero.Effect sizes for mediated effects were calculated using Kappa Squared (κ 2 ), as recommended by Preacher and Kelley [45], with values of 0.01 considered small, 0.09 considered medium, and 0.25 considered large effects.

Ethics statement
The study received ethical approval from the Medical Ethics Committee of Tongji Medical College of Huazhong University of Science and Technology, China, under the reference [2022] Ethics (S230).The researchers provided a detailed explanation of the study's objectives to the participants, ensuring their understanding of the research purpose.Additionally, a commitment was made to anonymize all data collected.Before participating in the study, each participant gave written informed consent.Significantly, participants were provided with unequivocal assurance regarding their absolute autonomy to discontinue their involvement in the study at any juncture.

Characteristics of the participants
A total of 230 patients with MHD participated in this study.The ages of the participants ranged from 24 to 88 years; the median age was 57 (44,74) years.The male gender constituted the majority of the participants (60.0%), while individuals with a high school education completion accounted for 30.0% of the sample.Furthermore, a significant proportion of the participants were married (75.7%), and their monthly income fell within the range of 2001-4000 RMB (30.9%).Additionally, 34.8% of the participants were suffering from two kinds of chronic comorbidities.Of these participants, 28.7% had kidney disease due to hypertension.Regarding the duration of hemodialysis, a total of 64 participants (27.8%) received hemodialysis treatments ranging from 1 to 3 years.The frequency of dialysis among the participants was mainly three times a week.

The relationships among IP, FOP, and social alienation
Table 1 showed that IP and FOP were both positively correlated with social alienation.Additionally, a statistically significant positive correlation was ascertained between IP and FOP.

The mediating role of FOP in the relationship between IP and social alienation
The results of the mediating role are presented in Tables 2 and 3. Within the framework of our study's mediation model, social alienation was considered the dependent variable, IP was the independent variable, and FOP was the mediating variable.To mitigate potential confounding effects and enhance the statistical power of the analysis, several covariates, namely age, gender, education level, marital status, monthly income, Primary cause, number of comorbidities, duration of hemodialysis, and dialysis frequency, were included in the 'Covariates module during the bootstrap procedure.This ensured that these variables were controlled to minimize their impact on the results.
The results indicate that there was a significant total effect (path c) of IP on social alienation, indicating a positive relationship between IP and social alienation.Moreover, significant coefficients were found for paths a and b, indicating a positive relationship between IP and FOP, as well as a positive correlation between FOP and social alienation.Additionally, the point estimate of the indirect effects (a * b) connecting IP to social alienation through FOP according to our analysis.We documented Kappa Squared values of 21.9% (κ2 = 0.219), suggesting the medium effect of the mediation by FOP in the relationship between IP and social alienation.A graphical representation of the final mediation model is displayed in Fig 2.

Comparing social alienation scores of participants with different characteristics
As illustrated in Table 4, notable variations in the total score of social alienation were observed across different factors, including education level, marital status, monthly income, number of comorbidities, duration of hemodialysis, and dialysis frequency.However, there was no significance among different genders, and primary causes (p > 0.05).

Discussion
Social alienation presents a common concern in the realm of mental health among MHD patients.However, the examination of FOP as a mediating factor in the relationship between IP and social alienation in MHD patients has remained unexplored in prior investigations.As evident from our current study, the results substantiate our initial hypothesis that there exists a positive correlation between IP, FOP, and social alienation among MHD patients.Furthermore, our findings suggest that FOP plays a mediating function between IP and feelings of social alienation.In essence, MHD patients with negative disease perceptions are inclined to harbor apprehensions regarding the progression of their condition, which, in turn, contributes to amplified levels of social alienation.

IP is positively correlated with social alienation
Similar to previous research [46,47], this study revealed a positive correlation between IP and social alienation.Illness cognition is a key factor in the interaction between psychology and illness.It can affect the patient's psychological state and determine his or her level of self-regulation [48].Positive disease awareness is conducive to enhancing their awareness of preventive health care and promoting medical compliance behaviors, thereby improving patients' health and long-term quality of life [49][50][51][52].However, the stronger the individual's negative disease perception, the more severe the symptoms they experience, which may aggravate the patient's negative emotions, reduce the confidence in coping with stressful events [19], reduce the individual's willingness to contact the surrounding things and the environment, and increase social alienation feel.CSM shows that as the disease and treatment progress, an individual's disease perception manifests itself as a dynamic process of constant modification and adjustment [53].

FOP is positively correlated with social alienation
Consistent with previous research [54], this study revealed a positive correlation between FOP and social alienation.The theoretical model for fear of cancer recurrence (FCR) suggests that the patient's experience of the illness generates FOP, which, in turn, leads to other negative emotions [55].A moderate level of fear can act as a motivating factor, encouraging patients to All path coefficient was standardized. (1)Primary school or below as reference; (2) Single as reference; (3) �2000 as reference; (4) Chronic nephritis as reference; (5) 0 as reference; (6) <1 as reference; (7) 2 as reference.
https://doi.org/10.1371/journal.pone.0301666.t002adopt healthy behaviors and positive treatment approaches [56].However, excessive fear functions as a strong inhibitor, putting patients in a negative state [57] when confronted with their illness and decreasing their quality of life [58,59].Researchers have found that individuals with lower FOP are more able to consciously control their social life activities and consider all sides of the disease, treatment, life, and work, resulting in less social alienation [33].Long-term excessive fear can cause chronic suffering [60], affecting patients' quality of life and social functioning.FOP is one of the most prominent psychological distresses in MHD patients [61], they may fear that the disease may be worse, require more complex treatment, or be at risk for complications, and this uncertainty may have a significant negative impact on their lives, leading to worry and anxiety about participating in social activities and increased social alienation [62].These results suggest that actively reducing FOP is an important way to reduce social alienation.

FOP as a mediator between IP and social alienation
The purpose of this study was to investigate the effects of IP on social alienation and examine the underlying mediating mechanism involving FOP.Noteworthy findings emerged, affirming our original hypothesis as FOP played a significant mediator in the association between IP and social alienation.Our findings suggest that patients who report negative IP have higher levels of FOP, which in turn leads to higher levels of social alienation.Especially in the early stages of hemodialysis treatment, patients have insufficient knowledge of the disease and hemodialysis and are fearful of complications [34,63,64], which causes them to overly focus on their diseases, resulting in a significant reduction in social activities and increased social alienation.Previous research has confirmed that negative disease perception is an internal stimulus and a significant predictor of higher fear of disease progression [65].More specifically, MHD patients with a positive and correct conception of the disease can better regulate their fears during the course of the disease progression [66].In other words, when people with MHD develop negative and discouraging perceptions of the disease, they may fear the severity and progression of the disease and doubt their health, which can lead to an increase in mental stress, negative emotions, and anxiety, (1) t-value; (2) H-value; (3) Z-value. https://doi.org/10.1371/journal.pone.0301666.t004 fear, and depression [67].These psychological reactions and emotional experiences may influence patients' well-being and their social behaviors [68], causing them to become more withdrawn and avoid social situations, leading to an increased level of social alienation.

The level of social alienation among MHD patients
In this study, it was found that the level of social alienation in MHD patients was identified to be moderately elevated, with a mean total score of 39.90 ± 6.22, which is similar to the results of previous research [25].There are several reasons why MHD patients have moderately high levels of social alienation.First, due to the need for regular dialysis treatments in hospitals two to three times a week and frequent travel between hospitals and their homes, MHD patients experience a change in their social roles, inability to work and socialize normally, and limited participation in social activities, which can lead to social alienation [69,70].Second, as a result of long-term hemodialysis, MHD patients' physical function, muscle strength, and functional motor ability have declined, their social function has gradually weakened, and they have become more dependent on their caregivers for support and assistance, which has brought double pressure on the patients' body and psychology, and exacerbated social alienation.Lastly, MHD patients have high rates of cardiovascular events and mortality [15,71], and patients have negative perceptions of the disease [72], leading to fear of disease progression and increased social alienation.

Practical implications
The findings of this study have important practical implications.On the one hand, the study's exploration of how IP influences social alienation through FOP offers insights into the psychological experiences of MHD patients.This understanding is crucial for fostering psychological resilience in patients, enabling them to better navigate the challenges of their illness.When patients adopt a more positive perspective on their condition and experience reduced social alienation, this can lead to increased treatment adherence, potentially improving overall health outcomes [43,73].Moreover, numerous studies have shown a strong correlation between social functioning and positive emotional state [74][75][76].By reducing social alienation among MHD patients, it is possible to enhance their experience of positive emotions and well-being, such as happiness, contentment, and gratitude, which are integral to contributing to positive psychology and to improving mental health and overall quality of life [77,78].On the other hand, the study's results contribute to revealing the underlying mechanisms of the psychological state of MHD patients, Providing a theoretical foundation for personalized interventions for healthcare professionals to improve patients' sense of social alienation.For instance, interventions such as cognitive restructuring to modify illness perceptions [79] and reduce the impact of FOP [80], along with specialized health education materials that deepen patients' understanding of their condition and treatment, can be effective [78,81].Additionally, specialized psychosocial interventions [82,83], including psychotherapeutic Support, relaxation-based interventions, and group therapy sessions, can assist patients in reshaping their thought processes, alleviating anxiety about disease progression, and subsequently reducing the sense of social alienation.
Furthermore, the use of digital tools and telemedicine platforms allows for the establishment of online support systems, providing patients with real-time assistance.These systems can include databases of medical information, online consultation forums, and virtual support groups, helping to bridge geographical distances and reduce social disconnection [84][85][86].Moreover, implementing continuous monitoring of patients' physical and mental health, with regular reassessments of their illness perceptions and psychosocial needs, can ensure that care plans are adapted as necessary [9,87].For patients experiencing severe psychological distress or significant functional limitations, accessible, intensive, and long-term professional support should be integrated into their care plans [88].

Limitations
This study has certain theoretical and practical significance, but it also has some limitations.Firstly, this study was a cross-sectional design, thus, it cannot infer a causal relationship between IP, FOP, and social alienation.Secondly, this study employed convenience sampling and self-reporting methods for data collection, which may introduce potential biases such as selection bias and reporting bias.Therefore, it is important to exercise caution in interpreting the results of this study.In future research, it is recommended to employ a combination of self-evaluation and external evaluations for data collection and consider using different sampling methods to validate the findings.Additionally, given the multifaceted nature of factors influencing the explanatory variables, it is important to acknowledge that IP, while analyzed in this study, represents only one aspect influencing patients' social alienation.Consequently, the developed mediation model should not be considered the sole mediation model, and it is essential to explore and test various other explanatory and mediating variables in future investigations.

Conclusion
To sum up, this study showed that MHD patients had moderately high levels of social alienation, that IP was a positive predictor of social alienation, that FOP was a positive predictor of social alienation, and that FOP played a mediating role between IP and social alienation in MHD patients.The findings suggest that reducing negative perceptions of the disease can reduce patients' fear of disease progression, thereby improving their social functioning and quality of life.Therefore, we suggest that disease cognition and fear assessment should be a routine task for MHD specialist nurses to help patients with more negative disease cognition in early stage to adjust themselves in time, to face the disease and treatment correctly, to reduce the fear of disease and complications, to promote participation in social activities, and to improve the quality of life of MHD patients.

( 1 )
Patients aged 18 years or above; (2) Patients who received regular hemodialysis for at least 3 months; (3) Patients possessing written and oral reading and communication abilities; (4) Patients who provided informed consent and voluntarily participated in this study.The participant exclusion criteria encompassed the following aspects: (1) Patients presenting with other significant and life-threatening illnesses; (2) Patients diagnosed with severe cognitive impairment or mental disorders; (3) Patients who dropped out or were unable to answer a complete questionnaire.